Metabolite Profiling and Integrative Modeling Reveal Metabolic Constraints for Carbon Partitioning under Nitrogen-Starvation in the Green Alga Haematococcus pluvialis

The green alga Haematococcus pluvialis accumulates large amounts of the antioxidant astaxanthin under inductive stress conditions, such as nitrogen starvation. The response to nitrogen starvation and high-light leads to the accumulation of carbohydrates and fatty acids, as well as increased activity...

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Bibliographic Details
Published inThe Journal of biological chemistry Vol. 289; no. 44; pp. 30387 - 30403
Main Authors Recht, Lee, Töpfer, Nadine, Batushansky, Albert, Sikron, Noga, Zarka, Aliza, Gibon, Yves Y., Nikoloski, Zoran, Fait, Aaron, Boussiba, Sammy
Format Journal Article
LanguageEnglish
Published American Society for Biochemistry and Molecular Biology 2014
Subjects
Life Sciences
Vegetal Biology
computational biology
systems biology
constraint-based modeling
nitrogen starvation
carbohydrate metabolism
metabolomics
fatty acid metabolism
Haematococcus pluvialis
algae
data integration
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Summary:The green alga Haematococcus pluvialis accumulates large amounts of the antioxidant astaxanthin under inductive stress conditions, such as nitrogen starvation. The response to nitrogen starvation and high-light leads to the accumulation of carbohydrates and fatty acids, as well as increased activity of the tricarboxylic acid cycle. Although the behavior of individual pathways is well-investigated, little is known about the systemic effects of the stress-response mechanism. Here we present time-resolved metabolite, enzyme activity, and physiological data that capture the metabolic response of H. pluvialis under nitrogen starvation and high-light. The data were integrated into a putative genome-scale model of the green alga to in silico test the hypothesis of underlying carbon partitioning. The model-based hypothesis testing reinforces the involvement of starch degradation to support fatty acid synthesis in the later stages of the stress response. In addition, our findings support a possible mechanism for the involvement of the increased activity of the tricarboxylic acid cycle in carbon repartitioning. Finally, the in vitro experiments and the in silico modeling presented here emphasize the predictive power of large-scale integrative approaches to pinpoint metabolic adjustment to changing environments.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M114.555144